Answer:
option C is correct (250 g)
Explanation:
Given data:
Half life of carbon-14 = 5700 years
Total amount of sample = 1000 g
Sample left after 11,400 years = ?
Solution:
First of all we will calculate the number of half lives passes during 11,400 years.
Number of half lives = time elapsed/ half life
Number of half lives = 11,400 years/5700 years
Number of half lives = 2
Now we will calculate the amount left.
At time zero = 1000 g
At first half life = 1000 g/2 = 500 g
At second half life = 500 g/2 = 250 g
Thus, option C is correct.
<span>Vinegar and baking soda react to form a new gaseous substance.
</span><span>The reaction between Vinegar and baking soda has been one of the most common examples of Chemical Reaction.</span>
Answer:
Explanation:
use the equation
moles = mass/mr
=19.9/79.5
=0.250moles of CuO
then do the same for
H = 2.02/1
=2.02
so CuO is the limiting reagent because there is less amount of it.
Hope this helps :)
Answer:
Y, Q, W, Z and X
Y > Q > W > Z > X
Explanation:
To know the most reactive element, the element will be able to displace other metal in it compound. We also have to observe if the reaction occur. If the reaction didn't occur, that means the element is not reactive than the metal found in the other reactant. Invariably their will be no displacement.
Q + w+ Reaction occurs
Q element displace the metal w in it compound . This means Q is more reactive.
x +z+ No reaction
No reaction here. This means x is less reactive than z as it couldn't displace z in it compound.
w + z+ Reaction occurs
w is more reactive than z as it displaces z in it compound.
Q+ + Y Reaction occurs
Y is more reactive than Q as it displaces Q in it compounds.
Therefore, the most reactive to the least reactive is arrange as follows.
Y, Q, W, Z and X
